• A correlation between A-scan echograms recorded clinically in vivo and histological studies of corresponding sections has been made in 42 eyes with intraocular pathological conditions. This study yielded both new and little known acoustic differential criteria for the diagnosis of retinoschisis, funnel-shaped vitreous detachments, serous as well as hemorrhagic retinal and choroidal detachments, intravitreal hemorrhages, and intraocular tumors. (Arch Ophthalmol 95:1387-1394, 1977)